MOST of us start smiling when the summer comes and it's no surprise - a little sunshine every day can boost your mood and also help to prevent a host of serious illnesses.

FOR years we have been told to cover up in the sun to cut the risk of getting skin cancer. But now it seems that a little bit of sunshine on your body is actually good for you.

Studies have shown that a sensible amount of sun reduces your risk of several cancers and other serious health conditions.

And it's all thanks to vitamin D, which is made by our bodies through the action of the sun's UVB rays on our skin.

Professor Michael Holick, of Boston University School of Medicine and author of The UV Advantage says:

"We get about 90 to 95 per cent of our vitamin D from the sun. "It is essential for absorbing calcium, keeping our bones healthy, and for protecting against serious chronic diseases later in life such as osteoporosis, Type II diabetes, multiple sclerosis and many common cancers."

He advises that we should go out in the sun without sunblock for between five and 15 minutes a day, at least three times a week in spring and summer, to boost our vitamin D levels. (SunFriend suggests using a SunFriend to determine how much sun you should get each day since the UV emitting rays change in intensity with the time of the year and the atmospheric conditions, and of course your skin color effects how much sun you should get. SunFriend tracks all of this for you)

You can also get vitamin D from your diet - oily fish, such as salmon and tuna, is a good source - as is margarine, milk, eggs and fortified breakfast cereals. But most of us simply don't eat healthily enough to get adequate amounts, leaving the sun as the primary source of this important vitamin.

Here are the top 15 ways in which the sun can improve your health...

1. It cheers you up

SUNSHINE boosts levels of serotonin - the body's natural happy hormone. That's why we tend to feel happier and more energetic when the sun shines. Regular sun can stave off moderate depression, particularly if combined with exercise, such as a walk in the park. It's also been shown that exercising outdoors creates more endorphins in the body than exercising indoors.

2. Reduces heart disease

A STUDY in the British Medical Journal showed that people in the UK are more likely to die of heart disease in winter than in summer, which is believed to be because of low levels of vitamin D. Where you live in the UK also matters. Blackpool has 27 per cent more hours of sunshine a year than Burnley - and 9 per cent fewer deaths from coronary heart disease.

Cholesterol levels also rise in winter, according to reports in medical magazine The Lancet, and this is because our vitamin D levels fall.

And Dr Holick found that exposing people with high blood pressure to UVB rays in a tanning salon lowers blood pressure by similar amounts as prescribed drugs.

3. Prevents diabetes

VITAMIN D may help to prevent the onset of diabetes. "A study in Finland found children given a vitamin D supplement for several years had an 80 per cent reduced risk of developing Type I diabetes as young adults," says Dr Holick.

A deficiency in vitamin D is also thought to contribute to Type II diabetes, according to a recent study by Dr Barbara Boucher at St Bartholomew's and the Royal London Hospitals.

4. Beats SAD

SEASONAL Affective Disorder (SAD) - or the winter blues - is a depression specifically caused by lack of sunlight. Lightboxes can be used to treat it, although increased exposure to natural sunlight is more beneficial. Get out for an hour's walk in the morning during autumn and winter months, and sit outside for 15 minutes a day in summer.

5. Helps prevent MS

MULTIPLE sclerosis (MS) is a disease of the central nervous system, leading to tremors and even paralysis. The cause is not known but scientists have noted that exposure to sunlight in childhood appears to dramatically reduce the risk of developing this disease in later life. Scientists have also noted that the incidence of MS is lower in sunnier countries.

6. Prevents cavities

THE sun could even help to keep your teeth strong. A dental study found the prevalence of cavities was greater in children from Scotland, the North-West, Wales and Merseyside - areas with less than average sunshine. The proportion of 12-year-olds with untreated cavities was three times greater in Scotland than in the South West Thames region.

7. Relieves aches and pains

Being out in the sun helps to warm the body's muscles and eases stiffness, reducing the pain caused by inflammatory conditions such as arthritis.

8. Reduces risk of cancers

ALTHOUGH over exposure to the sun increases your risk of skin cancer, vitamin D provided by sunlight can actually help to significantly reduce your risk of other types of cancer.

A study carried out by the US National Cancer Institute found that people exposed to high levels of sunlight were significantly less likely to die from breast and colon cancer. A similar effect was seen in bladder, womb, oesophagus and stomach cancer.

9. Boosts fertility

THE sun reduces levels of the hormone melatonin which suppresses fertility, so it is more likely you'll conceive in summer.

And sunlight not only makes you more fertile, it increases the length of your fertility. A study in Turkey discovered that women who get less than an hour of sunlight a week reach menopause seven to nine years earlier.

Sunlight also boosts testosterone levels in men, which makes summer the perfect time for baby-making.

10. Gives you more energy

MELATONIN also regulates sleep, so having lower levels of this hormone in your body gives you more get up and go. This is why you need less sleep in summer but still feel livelier. Plus, being woken by natural light rather than an alarm clock helps you feel more positive.

11. Eases IBD

PEOPLE with Crohn's disease or other inflammatory bowel disorders (IBD) generally have low levels of vitamin D in their bodies, according to several studies. Sunlight is the best way to boost vitamin D in these cases.

Although it is available in some foods (including meat, eggs, oily fish and some breakfast cereals), levels are low and poor absorption of fat - a common complication of inflammatory bowel disease - may make it difficult for sufferers to absorb vitamin D from their diet.

12. Beats period problems

ABOUT one in five women of childbearing age suffer from polycystic ovary disease which causes abnormal periods, unwanted body hair and infertility.

Half of 14 women treated with vitamin D and calcium by Dr Susan Thys-Jacobs at St Luke's-Roosevelt Hospital, Columbia University in New York, recovered normal periods and two became pregnant. Dr Thys-Jacobs also found that women with premenstrual syndrome are likely to be deficient in vitamin D.

13. Helps skin conditions

EXPOSURE to the sun can help to heal such skin conditions as psoriasis, acne and eczema. Regular controlled sun exposure is often prescribed for sufferers. For serious cases, contact your GP. For minor cases, try exposing affected areas of skin to the sun for up to 30 minutes before covering up or slapping on the sunscreen - but make sure you never burn.

14. Boosts your immune system

SUNLIGHT encourages the production of white blood cells, which help to boost your immune system and fight infection.

15. Helps you lose weight

HIGHER levels of serotonin in our bodies not only makes you feel happy but it also suppresses the appetite, so you'll eat less in warmer weather.

Go out in the sun at least three times a week to boost levels of vitamin D

STAY SAFE IN THE RAYS

YOUR skin starts to turn pink when you've been exposed to enough sun. It takes around half this time to produce vitamin D without risking your skin (usually between 10-15 minutes between 10am-3pm in the UK). It takes black and Asian skin up to six times longer to produce vitamin D.

SunFriend is the worlds first wearable sun tracker that keeps track of how much sun you are getting! SunFriend makes it easier to get enough sun (rather than guessing) and helps warn you against over-exposure. SunFriend senses how much UV is hitting your skin, even through clouds and works with every skin color and level of sensitivity. LEDs let you know your progress and flash when you have had enough!

Most people are not aware that back in 2010 the Indoor Tanning Industry (ITA) settled a dispute with the Federal Trade Commission (FTC) over misleading ads and statements being made regarding the health benefits of Indoor Tanning.

As a result a settlement was reached between the FTC and the ITA that ads that claim exposure to ultraviolet radiation produces vitamin D in the body, or make other claims about the effectiveness or usefulness of indoor tanning products or services for the body’s generation of vitamin D, must clearly and prominently make this disclosure:

“NOTICE: You do not need to become tan for your skin to make vitamin D. Exposure to ultraviolet radiation may increase the likelihood of developing skin cancer and can cause serious eye injury.”

Journal of the American College of Nutrition published a scientific consensus paper in June of 2015 that presents information to illustrate that UV exposure not only provides the benefits of vitamin D production, but also many additional health benefits not related to vitamin D. The report also stated that the current culture of sun avoidance in the United States carries with it both health risks and quantifiable harm.